Core changes to base theme

[rgrp]

Core changes to theme in order to make it easier to re-theme:

• page_heading
• side bar menu must be switchable (left to right) (through config or css)
• Expand optional head to be: optional css and optional js
  • optional_head can stay but add optional_js
  • That way we could move optional js to the bottom of the page to improve page load times.
• more divs.
• better labelling for css (and javascript)